Epidermal growth factor receptor (EGFR, also known as HER1 or ErbB1) is a member of the ErbB/HER family of type 1 receptor tyrosine kinases (RTKs). Other members of this family include ErbB2 (HER2 or Neu), ErbB3 (HER3) and ErbB4 (HER4). Known ligands for EGFR include epidermal growth factor (EGF) and transforming growth factor alpha (TGF-α). Ligand binding to EGFR induces tyrosine phosphorylation and receptor dimerization with other ErbB family members.
RTKs such as EGFR function to allow cells to respond to diverse external stimuli. However, aberrant activation and/or overexpression of EGFR is associated with the development and progression of several human cancers. Accordingly, EGFR is a target for anti-cancer therapies. Approved drugs targeting EGFR include small molecule inhibitors such as gefitinib (Iressa®) and erlotinib (Tarceva®), and anti-EGFR antibodies such as cetuximab (Erbitux®) and panitumumab (Vectibix®). Anti-EGFR antibodies are mentioned in, e.g., U.S. Pat. No. 4,943,533, U.S. Pat. No. 5,844,093, U.S. Pat. No. 7,060,808, U.S. Pat. No. 7,247,301, U.S. Pat. No. 7,595,378, U.S. Pat. No. 7,723,484, and U.S. Pat. No. 7,939,072. Nonetheless, there is a need in the art for novel EGFR antagonists, such as anti-EGFR antibodies, for the treatment of cancer and other related disorders.